#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
	int arr[4] = { 0 };
	int max = 0;
	int i;
	for (i = 0; i < 4; i++)
		scanf("%d", &arr[i]);
	for (i = 0; i < 4; i++)
		if (arr[i] > max)
			max = arr[i];
	printf("%d", max);
	return 0;
}